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From: Mike Leach <mike.leach@arm.com>
To: Yeoreum Yun <yeoreum.yun@arm.com>,
	James Clark <james.clark@linaro.org>, Leo Yan <leo.yan@arm.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Clark Williams <clrkwllms@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	nd@arm.com
Subject: Re: [PATCH v11 3/9] coresight: etm4x: fix inconsistencies with sysfs configuration
Date: Fri, 18 Sep 2026 14:49:09 +0100	[thread overview]
Message-ID: <bf0dea40-8dd1-4108-a3de-28288a31a668@arm.com> (raw)
In-Reply-To: <20260915-separate_etm_cfg_v2-v11-3-d2b258d51747@arm.com>

Hi,

On 9/15/26 12:34, Yeoreum Yun wrote:
> The current ETM4x configuration via sysfs can lead to
> several inconsistencies:
> 
>    - If the configuration is modified via sysfs while a perf session is
>      active, the running configuration may differ before a sched-out and
>      after a subsequent sched-in.
> 
>    - If a perf session and a sysfs session enable tracing concurrently,
>      the configuration from configfs may become corrupted.
> 
>    - There is a risk of corrupting drvdata->config if a perf session enables
>      tracing while cscfg_csdev_disable_active_config() is being handled in
>      etm4_disable_sysfs().
> 
> To resolve these issues, separate the configuration into:
> 
>    - active_config: the configuration applied to the current session
>    - config: the configuration set via sysfs
> 

I'll add a comment about naming here - active_config is a bit overloaded 
in the code as it is also used by the csconfig code to represent a 
loaded and active configuration - which may at some point be applied to 
the active_config above.

If active_config is for the current session then curr_config would work.

Additionally config also appears as a local pointer in many of the 
functions. If this is the sysfs config then sysfs_config would work better.

This should make all the code a lot more readable, and easier to spot 
exactly which config we are dealing with.



> Additionally:
> 
>    - Apply the configuration from configfs after taking the appropriate mode.
> 
>    - Since active_config and related fields are accessed only by the local CPU
>      in etm4_enable/disable_sysfs_smp_call() (similar to perf enable/disable),
>      remove the lock/unlock from the sysfs enable/disable path and
>      startup/dying_cpu except when to access config fields.
> 
> As the active_config is used for cfg-configfs, etmv4 doesn't need to set
> its lock for the cfg-configfs since the active_config is proceted by cs_mode
> otherwise it would make a possible cpu-stall when it get interrupt while
> setting the sysfs configuration.
> 
> Therefore, set the drv_spinlock for cfg-configfs as NULL and
> let the cfg-configfs disable irq without grap drv_spinlock when it is NULL.
> 
> Fixes: 54ff892b76c6 ("coresight: etm4x: splitting struct etmv4_drvdata")
> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> ---
>   drivers/hwtracing/coresight/coresight-config.c     |  18 ++--
>   drivers/hwtracing/coresight/coresight-config.h     |  22 ++++
>   drivers/hwtracing/coresight/coresight-etm4x-cfg.c  |  13 ++-
>   drivers/hwtracing/coresight/coresight-etm4x-core.c | 118 ++++++++++++---------
>   .../hwtracing/coresight/coresight-etm4x-sysfs.c    |   6 +-
>   drivers/hwtracing/coresight/coresight-etm4x.h      |   4 +-
>   6 files changed, 113 insertions(+), 68 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-config.c b/drivers/hwtracing/coresight/coresight-config.c
> index 4f72ae71b696e..0e296289f286d 100644
> --- a/drivers/hwtracing/coresight/coresight-config.c
> +++ b/drivers/hwtracing/coresight/coresight-config.c
> @@ -73,13 +73,12 @@ static void cscfg_init_reg_param(struct cscfg_feature_csdev *feat_csdev,
>   /* set values into the driver locations referenced in cscfg_reg_csdev */
>   static int cscfg_set_on_enable(struct cscfg_feature_csdev *feat_csdev)
>   {
> -	unsigned long flags;
>   	int i;
>   
> -	raw_spin_lock_irqsave(feat_csdev->drv_spinlock, flags);
> -	for (i = 0; i < feat_csdev->nr_regs; i++)
> -		cscfg_set_reg(&feat_csdev->regs_csdev[i]);
> -	raw_spin_unlock_irqrestore(feat_csdev->drv_spinlock, flags);
> +	scoped_guard(feat_csdev_lock, feat_csdev) {
> +		for (i = 0; i < feat_csdev->nr_regs; i++)
> +			cscfg_set_reg(&feat_csdev->regs_csdev[i]);
> +	}
>   	dev_dbg(&feat_csdev->csdev->dev, "Feature %s: %s",
>   		feat_csdev->feat_desc->name, "set on enable");
>   	return 0;
> @@ -88,13 +87,12 @@ static int cscfg_set_on_enable(struct cscfg_feature_csdev *feat_csdev)
>   /* copy back values from the driver locations referenced in cscfg_reg_csdev */
>   static void cscfg_save_on_disable(struct cscfg_feature_csdev *feat_csdev)
>   {
> -	unsigned long flags;
>   	int i;
>   
> -	raw_spin_lock_irqsave(feat_csdev->drv_spinlock, flags);
> -	for (i = 0; i < feat_csdev->nr_regs; i++)
> -		cscfg_save_reg(&feat_csdev->regs_csdev[i]);
> -	raw_spin_unlock_irqrestore(feat_csdev->drv_spinlock, flags);
> +	scoped_guard(feat_csdev_lock, feat_csdev) {
> +		for (i = 0; i < feat_csdev->nr_regs; i++)
> +			cscfg_save_reg(&feat_csdev->regs_csdev[i]);
> +	}
>   	dev_dbg(&feat_csdev->csdev->dev, "Feature %s: %s",
>   		feat_csdev->feat_desc->name, "save on disable");
>   }
> diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h
> index 90fd937d3bd83..ae6295e308131 100644
> --- a/drivers/hwtracing/coresight/coresight-config.h
> +++ b/drivers/hwtracing/coresight/coresight-config.h
> @@ -7,6 +7,7 @@
>   #ifndef _CORESIGHT_CORESIGHT_CONFIG_H
>   #define _CORESIGHT_CORESIGHT_CONFIG_H
>   
> +#include <linux/cleanup.h>
>   #include <linux/coresight.h>
>   #include <linux/types.h>
>   
> @@ -259,4 +260,25 @@ void cscfg_csdev_disable_config(struct cscfg_config_csdev *config_csdev);
>   /* reset a feature to default values */
>   void cscfg_reset_feat(struct cscfg_feature_csdev *feat_csdev);
>   
> +#define feat_csdev_lock(feat_csdev, flags)				\
> +	do {								\
> +		raw_spinlock_t *__lock = feat_csdev->drv_spinlock;	\
> +		typecheck(unsigned long, flags);			\
> +		if (__lock)						\
> +			raw_spin_lock_irqsave(__lock, flags);		\
> +	} while (0)
> +
> +#define feat_csdev_unlock(feat_csdev, flags)				\
> +	do {								\
> +		raw_spinlock_t *__lock = feat_csdev->drv_spinlock;	\
> +		typecheck(unsigned long, flags);			\
> +		if (__lock)						\
> +			raw_spin_unlock_irqrestore(__lock, flags);	\
> +	} while (0)
> +
> +DEFINE_LOCK_GUARD_1(feat_csdev_lock, struct cscfg_feature_csdev,
> +		    feat_csdev_lock(_T->lock, _T->flags),
> +		    feat_csdev_unlock(_T->lock, _T->flags),
> +		    unsigned long flags)
> +
>   #endif /* _CORESIGHT_CORESIGHT_CONFIG_H */
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> index e1a59b4345052..d24f533c623d0 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> @@ -47,7 +47,7 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
>   				   struct cscfg_regval_csdev *reg_csdev, u32 offset)
>   {
>   	int err = -EINVAL, idx;
> -	struct etmv4_config *drvcfg = &drvdata->config;
> +	struct etmv4_config *drvcfg = &drvdata->active_config;
>   	u32 off_mask;
>   
>   	if (((offset >= TRCEVENTCTL0R) && (offset <= TRCVIPCSSCTLR)) ||
> @@ -154,11 +154,14 @@ static int etm4_cfg_load_feature(struct coresight_device *csdev,
>   	int i = 0, err = 0;
>   
>   	/*
> -	 * essential we set the device spinlock - this is used in the generic
> -	 * programming routines when copying values into the drvdata structures
> -	 * via the pointers setup in etm4_cfg_map_reg_offset().
> +	 * drvdata structure of etm4 for configfs is active_config and
> +	 * this active_config is protected with csdev->mode by restricting
> +	 * access to active_config after mode changed to PERF or SYSFS.
> +	 *
> +	 * Therefore, it doesn't need to protected with etmv4_drvdata->spinlock
> +	 * to feature applying and set the NULL.
>   	 */
> -	feat_csdev->drv_spinlock = &drvdata->spinlock;
> +	feat_csdev->drv_spinlock = NULL;
>   
>   	/* process the register descriptions */
>   	for (i = 0; i < feat_csdev->nr_regs && !err; i++) {
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 2247ad55d4442..2df7f592bb5cf 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -239,6 +239,7 @@ void etm4_release_trace_id(struct etmv4_drvdata *drvdata)
>   struct etm4_enable_arg {
>   	struct etmv4_drvdata *drvdata;
>   	struct coresight_path *path;
> +	struct etmv4_config config;

drvdata contains both active_config and config - why the extra copy here?

>   	int rc;
>   };
>   
> @@ -264,10 +265,11 @@ static void etm4x_prohibit_trace(struct etmv4_drvdata *drvdata)
>   static u64 etm4x_get_kern_user_filter(struct etmv4_drvdata *drvdata)
>   {
>   	u64 trfcr = drvdata->trfcr;
> +	struct etmv4_config *config = &drvdata->active_config;
>   
> -	if (drvdata->config.mode & ETM_MODE_EXCL_KERN)
> +	if (config->mode & ETM_MODE_EXCL_KERN)
>   		trfcr &= ~TRFCR_EL1_ExTRE;
> -	if (drvdata->config.mode & ETM_MODE_EXCL_USER)
> +	if (config->mode & ETM_MODE_EXCL_USER)
>   		trfcr &= ~TRFCR_EL1_E0TRE;
>   
>   	return trfcr;
> @@ -275,7 +277,7 @@ static u64 etm4x_get_kern_user_filter(struct etmv4_drvdata *drvdata)
>   
>   /*
>    * etm4x_allow_trace - Allow CPU tracing in the respective ELs,
> - * as configured by the drvdata->config.mode for the current
> + * as configured by the drvdata->active_config.mode for the current
>    * session. Even though we have TRCVICTLR bits to filter the
>    * trace in the ELs, it doesn't prevent the ETM from generating
>    * a packet (e.g, TraceInfo) that might contain the addresses from
> @@ -286,12 +288,13 @@ static u64 etm4x_get_kern_user_filter(struct etmv4_drvdata *drvdata)
>   static void etm4x_allow_trace(struct etmv4_drvdata *drvdata)
>   {
>   	u64 trfcr, guest_trfcr;
> +	struct etmv4_config *config = &drvdata->active_config;
>   
>   	/* If the CPU doesn't support FEAT_TRF, nothing to do */
>   	if (!drvdata->trfcr)
>   		return;
>   
> -	if (drvdata->config.mode & ETM_MODE_EXCL_HOST)
> +	if (config->mode & ETM_MODE_EXCL_HOST)
>   		trfcr = drvdata->trfcr & ~(TRFCR_EL1_ExTRE | TRFCR_EL1_E0TRE);
>   	else
>   		trfcr = etm4x_get_kern_user_filter(drvdata);
> @@ -299,7 +302,7 @@ static void etm4x_allow_trace(struct etmv4_drvdata *drvdata)
>   	write_trfcr(trfcr);
>   
>   	/* Set filters for guests and pass to KVM */
> -	if (drvdata->config.mode & ETM_MODE_EXCL_GUEST)
> +	if (config->mode & ETM_MODE_EXCL_GUEST)
>   		guest_trfcr = drvdata->trfcr & ~(TRFCR_EL1_ExTRE | TRFCR_EL1_E0TRE);
>   	else
>   		guest_trfcr = etm4x_get_kern_user_filter(drvdata);
> @@ -492,7 +495,7 @@ static int etm4_enable_trace_unit(struct etmv4_drvdata *drvdata)
>   static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
>   {
>   	int i, rc;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   	struct coresight_device *csdev = drvdata->csdev;
>   	struct device *etm_dev = &csdev->dev;
>   	struct csdev_access *csa = &csdev->access;
> @@ -612,27 +615,44 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
>   static void etm4_enable_sysfs_smp_call(void *info)
>   {
>   	struct etm4_enable_arg *arg = info;
> +	struct etmv4_drvdata *drvdata;
>   	struct coresight_device *csdev;
> +	unsigned long cfg_hash;
> +	int preset;
>   
>   	if (WARN_ON(!arg))
>   		return;
>   
> -	csdev = arg->drvdata->csdev;
> -	if (!coresight_take_mode(csdev, CS_MODE_SYSFS)) {
> -		/* Someone is already using the tracer */
> -		arg->rc = -EBUSY;
> -		return;
> +	drvdata = arg->drvdata;
> +	csdev = drvdata->csdev;
> +
> +	drvdata->active_config = arg->config;

This can happen before the smp call removing the need for arg->config?

> +
> +	/* enable any config activated by configfs */
> +	cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);
> +	if (cfg_hash) {
> +		arg->rc = cscfg_csdev_enable_active_config(csdev,
> +							   cfg_hash,
> +							   preset);
> +		if (arg->rc)
> +			return;
>   	}
>   
> -	arg->rc = etm4_enable_hw(arg->drvdata);
> +	drvdata->trcid = arg->path->trace_id;
>   
> -	/* The tracer didn't start */
> +	/* Tracer will never be paused in sysfs mode */
> +	drvdata->paused = false;
> +
> +	arg->rc = etm4_enable_hw(drvdata);
>   	if (arg->rc) {
> -		coresight_set_mode(csdev, CS_MODE_DISABLED);
> +		cscfg_csdev_disable_active_config(csdev);
>   		return;
>   	}
>   
> +	drvdata->sticky_enable = true;
>   	csdev->path = arg->path;
> +
> +	return;
>   }
>   
>   /*
> @@ -669,7 +689,7 @@ static int etm4_config_timestamp_event(struct etmv4_drvdata *drvdata,
>   {
>   	int ctridx;
>   	int rselector;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   
>   	/* No point in trying if we don't have at least one counter */
>   	if (!drvdata->nr_cntr)
> @@ -752,7 +772,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
>   {
>   	int ret = 0;
>   	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   	struct perf_event_attr max_timestamp = {
>   		.ATTR_CFG_FLD_timestamp_CFG = U64_MAX,
>   	};
> @@ -919,46 +939,36 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa
>   {
>   	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>   	struct etm4_enable_arg arg = { };
> -	unsigned long cfg_hash;
> -	int ret, preset;
> +	int ret;
>   
> -	/* enable any config activated by configfs */
> -	cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);
> -	if (cfg_hash) {
> -		ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);
> -		if (ret) {
> -			etm4_release_trace_id(drvdata);
> -			return ret;
> -		}
> +	if (!coresight_take_mode(csdev, CS_MODE_SYSFS)) {
> +		/* Someone is already using the tracer */
> +		return -EBUSY;
>   	}
>   
> -	raw_spin_lock(&drvdata->spinlock);
> -
> -	drvdata->trcid = path->trace_id;
> -
> -	/* Tracer will never be paused in sysfs mode */
> -	drvdata->paused = false;
> -
>   	/*
>   	 * Executing etm4_enable_hw on the cpu whose ETM is being enabled
>   	 * ensures that register writes occur when cpu is powered.
>   	 */
>   	arg.drvdata = drvdata;
>   	arg.path = path;
> +
> +	scoped_guard(raw_spinlock, &drvdata->spinlock) {
> +		arg.config = drvdata->config;

Given as mentioned above that once a mode is set then active_config is 
protected, this should simply be drvdata->active_config = 
drvdata->config; ??

> +	}
> +
>   	ret = smp_call_function_single(drvdata->cpu,
>   				       etm4_enable_sysfs_smp_call, &arg, 1);
>   	if (!ret)
>   		ret = arg.rc;
> -	if (!ret)
> -		drvdata->sticky_enable = true;
> -
> -	if (ret)
> +	if (!ret) {
> +		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
> +	} else {
>   		etm4_release_trace_id(drvdata);
> +		/* The tracer didn't start */
> +		coresight_set_mode(csdev, CS_MODE_DISABLED);
> +	}
>   
> -	raw_spin_unlock(&drvdata->spinlock);
> -
> -	if (!ret)
> -		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
>   	return ret;
>   }
>   
> @@ -1044,7 +1054,7 @@ static void etm4_disable_trace_unit(struct etmv4_drvdata *drvdata)
>   static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
>   {
>   	u32 control;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   	struct coresight_device *csdev = drvdata->csdev;
>   	struct csdev_access *csa = &csdev->access;
>   	int i;
> @@ -1086,8 +1096,9 @@ static void etm4_disable_sysfs_smp_call(void *info)
>   
>   	etm4_disable_hw(drvdata);
>   
> +	cscfg_csdev_disable_active_config(drvdata->csdev);
> +
>   	drvdata->csdev->path = NULL;
> -	coresight_set_mode(drvdata->csdev, CS_MODE_DISABLED);
>   }
>   
>   static int etm4_disable_perf(struct coresight_device *csdev,
> @@ -1130,8 +1141,9 @@ static int etm4_disable_perf(struct coresight_device *csdev,
>   static void etm4_disable_sysfs(struct coresight_device *csdev)
>   {
>   	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> -
> -	raw_spin_lock(&drvdata->spinlock);
> +	struct etmv4_config *config = &drvdata->config;
> +	const struct etmv4_config *active_config = &drvdata->active_config;
> +	int i;
>   
>   	/*
>   	 * Executing etm4_disable_hw on the cpu whose ETM is being disabled
> @@ -1140,9 +1152,17 @@ static void etm4_disable_sysfs(struct coresight_device *csdev)
>   	smp_call_function_single(drvdata->cpu, etm4_disable_sysfs_smp_call,
>   				 drvdata, 1);
>   
> -	raw_spin_unlock(&drvdata->spinlock);
> +	/*
> +	 * Userspace may read ss_status and cntr_val through sysfs after
> +	 * the sysfs-session has been disabled.
> +	 */
> +	for (i = 0; i < drvdata->nr_ss_cmp; i++)
> +		config->ss_status[i] = active_config->ss_status[i];
>   
> -	cscfg_csdev_disable_active_config(csdev);
> +	for (i = 0; i < drvdata->nr_cntr; i++)
> +		config->cntr_val[i] = active_config->cntr_val[i];
> +

Readback of TRCSEQSTR needed here too.

> +	coresight_set_mode(drvdata->csdev, CS_MODE_DISABLED);
>   
>   	/*
>   	 * we only release trace IDs when resetting sysfs.
> @@ -1690,7 +1710,7 @@ static void etm4_set_default(struct etmv4_config *config)
>   static int etm4_get_next_comparator(struct etmv4_drvdata *drvdata, u32 type)
>   {
>   	int nr_comparator, index = 0;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   
>   	/*
>   	 * nr_addr_cmp holds the number of comparator _pair_, so time 2
> @@ -1731,7 +1751,7 @@ static int etm4_set_event_filters(struct etmv4_drvdata *drvdata,
>   {
>   	int i, comparator, ret = 0;
>   	u64 address;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   	struct etm_filters *filters = event->hw.addr_filters;
>   
>   	if (!filters)
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> index 8d73248b840a6..f64c0acebc701 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> @@ -1613,7 +1613,7 @@ static ssize_t cntr_val_store(struct device *dev,
>   		return -EINVAL;
>   	if (val > ETM_CNTR_MAX_VAL)
>   		return -EINVAL;
> -	if (coresight_get_mode(drvdata->csdev))
> +	if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS)
>   		return -EBUSY;
>   
>   	raw_spin_lock(&drvdata->spinlock);
> @@ -1799,7 +1799,7 @@ static ssize_t sshot_ctrl_store(struct device *dev,
>   
>   	if (kstrtoul(buf, 16, &val))
>   		return -EINVAL;
> -	if (coresight_get_mode(drvdata->csdev))
> +	if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS)
>   		return -EBUSY;
>   
>   	raw_spin_lock(&drvdata->spinlock);
> @@ -1851,7 +1851,7 @@ static ssize_t sshot_pe_ctrl_store(struct device *dev,
>   
>   	if (kstrtoul(buf, 16, &val))
>   		return -EINVAL;
> -	if (coresight_get_mode(drvdata->csdev))
> +	if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS)
>   		return -EBUSY;
>   
>   	raw_spin_lock(&drvdata->spinlock);
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> index df9e0748d71ec..c33700711154d 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> @@ -1019,7 +1019,8 @@ struct etmv4_save_state {
>    *		allows tracing at all ELs. We don't want to compute this
>    *		at runtime, due to the additional setting of TRFCR_CX when
>    *		in EL2. Otherwise, 0.
> - * @config:	structure holding configuration parameters.
> + * @active_config:	structure holding current applied configuration.
> + * @config:	structure holding sysfs mode configuration.
>    * @save_state:	State to be preserved across power loss
>    * @skip_power_up: Indicates if an implementation can skip powering up
>    *		   the trace unit.
> @@ -1077,6 +1078,7 @@ struct etmv4_drvdata {
>   	bool				skip_power_up : 1;
>   	bool				paused : 1;
>   	u64				trfcr;
> +	struct etmv4_config		active_config;
>   	struct etmv4_config		config;
>   	struct etmv4_save_state		*save_state;
>   	DECLARE_BITMAP(arch_features, ETM4_IMPDEF_FEATURE_MAX);
> 

Regards

Mike


  parent reply	other threads:[~2026-09-18 13:49 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-15 11:34 [PATCH v11 0/9] fix several inconsistencies with sysfs configuration in etmX Yeoreum Yun
2026-09-15 11:34 ` [PATCH v11 1/9] coresight: etm4x: prohibit modifying ss_status and cntr_val while session is enabled Yeoreum Yun
2026-09-15 11:51   ` sashiko-bot
2026-09-15 13:26     ` Yeoreum Yun
2026-09-18 11:14   ` Mike Leach
2026-09-18 17:08     ` Yeoreum Yun
2026-09-15 11:34 ` [PATCH v11 2/9] coresight: etm3x: prohibit modifying cntr_val and reset " Yeoreum Yun
2026-09-15 11:48   ` sashiko-bot
2026-09-15 13:30     ` Yeoreum Yun
2026-09-15 13:55       ` Yeoreum Yun
2026-09-18 11:15   ` Mike Leach
2026-09-15 11:34 ` [PATCH v11 3/9] coresight: etm4x: fix inconsistencies with sysfs configuration Yeoreum Yun
2026-09-15 11:53   ` sashiko-bot
2026-09-15 12:36     ` Yeoreum Yun
2026-09-18 13:49   ` Mike Leach [this message]
2026-09-18 17:00     ` Yeoreum Yun
2026-09-15 11:34 ` [PATCH v11 4/9] coresight: etm3x: " Yeoreum Yun
2026-09-15 11:47   ` sashiko-bot
2026-09-15 13:42     ` Yeoreum Yun
2026-09-18 13:57   ` Mike Leach
2026-09-18 17:09     ` Yeoreum Yun
2026-09-15 11:34 ` [PATCH v11 5/9] coresight: etm3x: remove redundant cpu online check on etm_enable_sysfs() Yeoreum Yun
2026-09-18 13:58   ` Mike Leach
2026-09-15 11:34 ` [PATCH v11 6/9] coresight: etm4x: introduce struct etm4_caps Yeoreum Yun
2026-09-18 14:01   ` Mike Leach
2026-09-15 11:34 ` [PATCH v11 7/9] coresight: etm4x: exclude ss_status from drvdata->config Yeoreum Yun
2026-09-15 11:49   ` sashiko-bot
2026-09-15 13:35     ` Yeoreum Yun
2026-09-18 14:04   ` Mike Leach
2026-09-18 17:13     ` Yeoreum Yun
2026-09-15 11:34 ` [PATCH v11 8/9] coresight: etm4x: remove s_ex_level from config Yeoreum Yun
2026-09-18 14:05   ` Mike Leach
2026-09-15 11:34 ` [PATCH v11 9/9] coresight: etm3x: introduce struct etm_caps Yeoreum Yun
2026-09-18 14:57   ` Mike Leach

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